Regulatory Matters (Regulatory Capital Levels) (Details) $ in Thousands	Sep. 30, 2022 USD ($)	Dec. 31, 2021 USD ($)
SmartFinancial, Inc. [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Total Capital (to Risk-Weighted Assets), Actual Amount	$ 412,647	$ 386,627
Tier 1 Capital (to Risk-Weighted Assets), Actual Amount	347,884	325,345
Common Equity Tier 1 Capital (to Risk-Weighted Assets), Actual Amount	347,884	325,345
Tier 1 Capital (to Average Assets), Actual Amount	$ 347,884	$ 325,345
Total Capital (to Risk-Weighted Assets), Actual Ratio (as a percent)	0.1144	0.1255
Tier 1 Capital (to Risk-Weighted Assets), Actual Ratio (as a percent)	0.0965	0.1056
Common Equity Tier 1 Capital (to Risk-Weighted Assets), Actual Ration (as percent)	0.0965	0.1056
Tier 1 Capital (to Average Assets), Actual Ratio (as a percent)	0.0740	0.0745
Total Capital (to Risk-Weighted Assets), Minimum for capital adequacy purposes Amount	$ 288,445	$ 246,483
Tier 1 Capital (to Risk-Weighted Assets), Minimum for capital adequacy purposes Amount	216,334	184,862
Common Equity Tier 1 Capital (to Risk-Weighted Assets), Minimum for capital adequacy purposes Amount	162,250	138,647
Tier 1 Capital (to Average Assets), Minimum for capital adequacy purposes Amount	$ 188,070	$ 174,578
Total Capital (to Risk-Weighted Assets), Minimum for capital adequacy purposes Ratio (as a percent)	0.0800	0.0800
Tier 1 Capital (to Risk-Weighted Assets), Minimum for capital adequacy purposes Ratio (as a percent)	0.0600	0.0600
Common Equity Tier 1 Capital (to Risk-Weighted Assets), Minimum for capital adequacy purposes Ratio (as a percent)	0.0450	0.0450
Tier 1 Capital (to Average Assets), Minimum for capital adequacy purposes Ratio (as a percent)	0.0400	0.0400
Smart Bank [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Total Capital (to Risk-Weighted Assets), Actual Amount	$ 411,529	$ 378,055
Tier 1 Capital (to Risk-Weighted Assets), Actual Amount	388,760	358,703
Common Equity Tier 1 Capital (to Risk-Weighted Assets), Actual Amount	388,760	358,703
Tier 1 Capital (to Average Assets), Actual Amount	$ 388,760	$ 358,703
Total Capital (to Risk-Weighted Assets), Actual Ratio (as a percent)	0.1141	0.1229
Tier 1 Capital (to Risk-Weighted Assets), Actual Ratio (as a percent)	0.1078	0.1166
Common Equity Tier 1 Capital (to Risk-Weighted Assets), Actual Ration (as percent)	0.1078	0.1166
Tier 1 Capital (to Average Assets), Actual Ratio (as a percent)	0.0827	0.0823
Total Capital (to Risk-Weighted Assets), Minimum for capital adequacy purposes Amount	$ 288,523	$ 246,053
Tier 1 Capital (to Risk-Weighted Assets), Minimum for capital adequacy purposes Amount	216,392	184,539
Common Equity Tier 1 Capital (to Risk-Weighted Assets), Minimum for capital adequacy purposes Amount	162,294	138,405
Tier 1 Capital (to Average Assets), Minimum for capital adequacy purposes Amount	$ 188,071	$ 174,384
Total Capital (to Risk-Weighted Assets), Minimum for capital adequacy purposes Ratio (as a percent)	0.0800	0.0800
Tier 1 Capital (to Risk-Weighted Assets), Minimum for capital adequacy purposes Ratio (as a percent)	0.0600	0.0600
Common Equity Tier 1 Capital (to Risk-Weighted Assets), Minimum for capital adequacy purposes Ratio (as a percent)	0.0450	0.0450
Tier 1 Capital (to Average Assets), Minimum for capital adequacy purposes Ratio (as a percent)	0.0400	0.0400
Total Capital (to Risk-Weighted Assets), Minimum to be well capitalized under prompt corrective action provisions Amount	$ 360,653	$ 307,566
Tier 1 Capital (to Risk-Weighted Assets), Minimum to be well capitalized under prompt corrective action provisions Amount	288,523	246,053
Common Equity Tier 1 Capital (to Risk-Weighted Assets), Minimum to be well capitalized under prompt corrective action provisions Amount	234,425	199,918
Tier 1 Capital (to Average Assets), Minimum to be well capitalized under prompt corrective action provisions Amount	$ 235,089	$ 217,980
Total Capital (to Risk-Weighted Assets), Minimum to be well capitalized under prompt corrective action provisions Ratio (as a percent)	0.1000	0.1000
Tier 1 Capital (to Risk-Weighted Assets), Minimum to be well capitalized under prompt corrective action provisions Ratio (as a percent)	0.0800	0.0800
Common Equity Tier 1 Capital (to Risk-Weighted Assets), Minimum to be well capitalized under prompt corrective action provisions Ratio (as a percent)	0.0650	0.0650
Tier 1 Capital (to Average Assets), Minimum to be well capitalized under prompt corrective action provisions Ratio (as a percent)	0.0500	0.0500